What is 30% of 30? 9 30% of 30 Copy 30% of 30 = 9. Formula UsedResult = (30 ÷ 100) × 30 = 9 Frequently Asked Questions What is 30% of 30?9. (30 ÷ 100) × 30 = 9.How to calculate 30%?Multiply by 0.3 (or multiply by 30 then divide by 100).